Radish growing profile.

Radish Companion Plants

What may help, what can compete, and where the evidence is still uncertain.

Radish Raphanus sativus

Cool-season vegetable in the cabbage family. View plant profile →

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Quick answer

Evidence supports or conditionally supports growing radish with Carrot. 1 traditional pairing is listed separately because the review found no adequate evidence. 1 popular pairing has no verified relationship, which is not the same as safe or harmful.

Every status below has a direction, mechanism, context and source. "No verified relationship" means we looked and found nothing usable; the planner then evaluates spacing, light, water and timing normally. How we classify evidence →

Conditional benefit (1)

Positive only when the stated conditions match; otherwise informational.

CarrotDaucus carota subsp. sativusConditionalRelay or sequence Radish may affect CarrotSpring–Fall · relay · Mixed in the same row at low radish de…Tier C Review: August 15, 2026

Why?

Claim. Radishes sown in the same row as slow-germinating carrots mark the row, break the soil crust and are harvested before the carrots need the space; a relay in time rather than a biological interaction.

Mechanism. Different maturity dates let two crops use the same row in sequence.

Conditions. Sow together; pull radishes at 3–4 weeks. Mixed in the same row at low radish density. Short overlap only; remove radishes promptly.

Management. Pull radishes before they crowd carrot seedlings.

Applies when. Any carrot sowing.

Limitations. Radishes left too long compete with carrot seedlings; both are hosts for different root pests.

Evidence. Tier C: Indirect evidence: greenhouse or pot work, a related crop or species, or credible extension guidance with important uncertainty. (extension synthesis).

Sources. Cornell University 2024; Royal Horticultural Society 2025; Brooker 2015

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record radish--carrot--temporal_complement v1. Request a correction.

Traditional claim (1)

Never a hard rule; may appear as an optional experiment.

Traditional claims are shown separately because repetition across charts is not evidence. They never change a planner score; treat them as optional experiments.

CucumberCucumis sativusTraditionalPest suppression · cucumber beetles Radish may affect CucumberSummer · arrangement unspecifiedTier D Review: August 15, 2026

Why?

Claim. Radishes are said to deter cucumber beetles. No controlled evidence found.

Mechanism. Proposed by tradition; not demonstrated in a controlled comparison.

Conditions. Planted together Both plants must be present at the same time.

Applies when. Optional experiment, not a guarantee.

Limitations. Tradition only.

Evidence. Tier D: Traditional knowledge or structured community observations without a controlled comparison. (tradition).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record radish--cucumber--pest_suppression v1. Request a correction.

**A realistic garden scene where radish grows beside a plant with a traditional or unknown relationship.**Coexistence in a photograph is not evidence that the plants affect each other.

No verified relationship (1)

Zero score and an honest unknown state. Spacing, light, water and timing are evaluated normally.

No verified relationship: we did not find a source that establishes a benefit or harm for these pairs. This is not the same as "compatible".

LettuceLactuca sativaNo verified relationshipOther Radish and Lettuce affect each other (mutual)Spring–Fall · arrangement unspecifiedUnknown Review: August 15, 2026

Why?

Claim. We did not find a source that establishes a benefit or harm between lettuce and radish.

Mechanism. None documented.

Conditions. Planted together Both plants must be present at the same time.

Applies when. The planner evaluates spacing, light, water and timing normally.

Limitations. Commonly interplanted for space; no benefit or harm documented.

Evidence. Unknown: No source meeting the inclusion rules. (none).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record lettuce--radish--other v1. Request a correction.

Example layout for radish

Documented arrangement with Carrot: relay. Mixed in the same row at low radish density. Sow together; pull radishes at 3–4 weeks.

Worked example based on the record, not a photograph of a trial.

**Side view of radish (15–20 cm) beside typical companions, showing canopy, support, shade and access.**

When these companions overlap

Bed occupancy in Portland, Oregon (estimates). A relationship only matters while both plants are present.

Radish

Carrot35 wk overlap

Cucumber19 wk overlap

Lettuce36 wk overlap

Overlap in weeks
Carrot	35 weeks
Cucumber	19 weeks
Lettuce	36 weeks

Crop rotation guidance

Rotation is about what occupied the bed in previous seasons and is calculated separately from the live companion relationships above.

Rotate radish on a 3-year cycle with other cabbage family crops (Cabbage, Broccoli, Cauliflower, Kale, Brussels sprouts). Shared risks: clubroot, cabbage root fly, cabbage white caterpillars.

Crop rotation hub · Brassicaceae family page

Physical and resource fit

Cucumber: Cucumber would shade Radish.

Fit checks come from plant attributes and apply even when a pairing has a positive claim.

Community observations (anecdotal)

These reports come from gardeners and are not reviewed evidence. Results vary with soil, climate and practice. Community data never changes an evidence tier or a planner score.

Reports for radish: 0 (community submissions open in a later phase; drafts are stored only on your device).

**Community-submitted photo area (moderated) with context fields: region, season, layout, varieties, outcome.**

Record an observation

Evidence summary and sources

Vegetable Growing Guides — Cornell University, 2024 (guidance)
Grow Your Own vegetables, herbs and fruit — Royal Horticultural Society, 2025 (guidance)
Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology — New Phytologist, 2015 (synthesis)
Companion planting in home gardens — University of Minnesota Extension, 2023 (guidance)

Reviewer: Garden Planner editorial team (pending independent horticultural review). Status counts on the Companions A–Z page are derived from these records. Corrections.

Radish Companion Plants

Quick answer

Conditional benefit (1)

Traditional claim (1)

No verified relationship (1)

No records match those filters

Example layout for radish

When these companions overlap

Crop rotation guidance

Physical and resource fit

Community observations (anecdotal)

Evidence summary and sources

Related

Visual evidence on this page

Our Methodology & Sources